I grew some grass for our cat Chance at work. She's a complete indoor cat, so doesn't see the real stuff too often unless I grow some. She sometimes makes a mess of my houseplants by chewing on them. My co-worker and friend Susan joined in to grow a pot for her cat Bettie. I had some seed packets which were meant for cats, so reading the contents I improvised a seed mix of rye grass (regular lawn seed), oat berries, wheat berries, and spelt berries. The latter three were from the pantry. Most of it sprouted just fine and within a week and a half I had this cat treat.
Chance took to it right away.
Yum! That was last night. This morning I found some puked up grass and foamy cat stuff on the floor. I think they are supposed to like doing that. I hope.